Anadrill -_2_days_stuck_pipe_1st
Transcript of Anadrill -_2_days_stuck_pipe_1st
Stuck Pipe Prevention
Prentice & Hill, LLC
First Day
Hydrostatic Pressure
Where: MW = Mud Weight (ppg) TVD = True Vertical Depth (ft) P = Hydrostatic Pressure (psi)
MEMORIZE THIS EQUATION!!
TVDMWP 052.
Hole Volumes
1029
2DV
V = Hole Volume in BBL/FT
D = Hole Diameter in INCHES
1029
22io
Annulus
DDV
Pressure - Area Forces
F P x A
F = Force (lbs)P = Pressure (psi)A = Area (sq-in)
F Ff n
Ff = Force Due to Friction (lbs) = Coefficient of Friction or Friction FactorFn = “Normal” Force (lbs)
Stuck Pipe
Most Common “Trouble” in Overspent WellsAvoiding Stuck Pipe
Understand Different Mechanisms Plan to Avoid Problems Recognize Symptoms Real Time Take Proper Actions While Drilling Use Recovery Procedures, if necessary
Solids Induced Pack-off
Formation Movement
Inadequate Hole Cleaning
CAUSES
Solids Induced Pack-off
Formation Loose w/ Little or No Bonding Insufficient Hydrostatic to Hold Back
Formation
UNCONSOLIDATED FORMATIONS
Causes
Pack-off Due to Unconsolidated Formations
Prevention
Gel up Mud / Run Hi Vis SweepsControl DrillSpot Gel Pill Prior to TOH
Plan / Anticipate:
Solids Induced Pack-off
Increase Mud Weight, if possibleUse Under-saturated Water Base MudPump Fresh Water SweepsDesign Casing to Handle Collapse Loads
Causes
MOBILE / PLASTIC FORMATIONS
Formation Extrudes Into Well Bore Due to Overburden Forces.
Prevention
Proper Well Planning:
Solids Induced Pack-off
Causes
Control Drill & Ream ConnectionsAnticipate Reaming on Trips
FRACTURED / FAULTED FORMATIONS
Prevention
Loose Chunks of Rock Fall into Well Bore
Plan / Anticipate
Solids Induced Pack-off
Causes
Raise Mud Weight, if possibleSet Casing Appropriately
OVER-PRESSURED SHALE COLLAPSE
Prevention
Shale “Pops” Off Wall Due to Pressure
Plan / Anticipate
Solids Induced Pack-off
Causes
Use Inhibited Mud SystemMinimize Exposure TimeBe Prepared for “Gumbo Attack”
REACTIVE FORMATIONS
Prevention
Mud Filtrate Reacts Chemically with Formation
Plan / Anticipate
Solids Induced Pack-off
Causes
Increase Annular VelocitiesBetter Mud Properties
Subject of another section
POOR HOLE CLEANING
Prevention
Not Removing Cuttings From Well Bore
Differential StickingCauses
High Differential Pressures• Excessive Mud Weight
• Drawn Down Formations
• Poor Well Planning
Well Bore ContactPoor Filter CakeLittle or No Pipe Motion
Differential Sticking - Prevention
Minimize Mud WeightImprove Filter CakeSelect Proper Casing SeatMinimize Contact Area
Stabilizers Heavy Weight Drill Pipe Spiral Drill Collars
Keep Pipe Moving
Plan / Anticipate
Mechanical / Wellbore Geometry Sticking
Causes KEYSEATING
Minimize Dog Leg SeverityCase Off Curves Soon After BuildingUse Keyseat WiperMake Frequent Wiper TripsBack Ream Out of Hole
• Abrupt Change in Well Bore Path (Dog Leg)• Long Hole Section Below Dog Leg
Prevention
Mechanical / Wellbore Geometry Sticking
Causes UNDERGAUGE HOLE
Always Gauge Bit & Stabilizers IN and OUTRun Gauge Protected Bits & StabilizersReam Suspected Undergauge Sections
• Undergauge Bit and/or Stabilizers• Coring (Core heads slightly U.G.)
Prevention
Mechanical / Wellbore Geometry Sticking
Causes LEDGES & DOGLEGS
Run Packed Hole AssembliesReam on Trips Through Problem Zones
• Limber BHAs• Hard - Soft Interbedded Formation
Prevention
Mechanical / Wellbore Geometry StickingCauses
SHOE JOINT BACKS OFF
Do Not Overdisplace CementThread Lock Bottom 3 Joints of CasingDrill Out Carefully
Prevention
Mechanical / Wellbore Geometry Sticking
Causes GREEN CEMENT
Wash Down Carefully to “Top of Cement”Pre-Treat Mud Before Drilling Green
Cement
Prevention
Run BHA Into Un-set Cement
Mechanical / Wellbore Geometry Sticking
Causes JUNK
Good Housekeeping on Rig FloorKeep Hole CoveredInspect Equipment Frequently
Prevention
Something Manmade is Loose in the Hole
Mechanical / Wellbore Geometry Sticking
Causes CEMENT BLOCKS
Set All Casing As Close To TD As PossibleReam Casing Shoe & Open Hole Plugs Before
Drilling Ahead
Hard Cement Falls In From Casing Shoe or FromOpen Hole Cement Plug
Prevention
Mechanical / Wellbore Geometry Sticking
Causes LINER & SQUEEZE CEMENTING
Hazards in Liner Cementing Too Much Excess Overdisplacement
Squeeze Cementing Hold Pressure on Back Side, If Possible Use Cement Retainers DO NOT Cement Up a Squeeze Packer (RTTS)
Cementing Yourself in the Hole
MUD
Mud Types / Constituents Water Base Mud Oil Base Mud Synthetic Base Mud
Primary Functions (Review) Remove Cuttings Lubricate and Cool Bit Provide Hydrostatic
Mud (continued)
Filter Cake “2/32”Fluid Loss
API Fluid Loss• Room Temperature
• 100 psi differential
Mud (continued)
Filter Cake “2/32”Fluid Loss
API Fluid Loss• Room Temperature
• 100 psi differential High Temperature, High Pressure (HTHP)
• 300º F or as specified
• 500 psi differential
Mud (continued)
Rheological Properties Measured with Fann Viscometer Funnel Viscosity Plastic Viscosity Yield Point
Mud (continued)
Mud Additives Gel (Wyoming Bentonite) Barite Chemicals Lost Circulation / Stuck Pipe Preventatives
• Sized Particulate Matter
• Fibrous Material
• Asphalt
• Snake Oil
Influence of Mud Properties on Various Stuck Pipe Mechanisms
Inadequate Hole Cleaning
Near Vertical Wells (Incl < 30 deg) Stabilize Hole Maintain Good Annular Velocity Keep Low Shear Rate Viscosities High
• Yield Stress = 2 (6 - 3)
• Gel Strength Do Not Overload Hole Due to Too High ROP Clean Hole Prior to Trip
Inadequate Hole Cleaning
Most Difficult Angle to Clean Hole Unstable Cuttings Beds Form Beds May Avalanche Even With Pumps On Raising Mud Viscosity Alone Will Not Solve M-I Video of Hole Cleaning
Moderate Angle Wells (30° <Incl < 60°)
Inadequate Hole Cleaning Moderate Angle Wells (30° <Incl < 60°)
Anticipate Problem - Alert for Symptoms Erratic Pump Pressure Reduced Returns at Shaker for ROP Erratic PWD Data Increasing Overpull 5-10 Stands Off Bottom It Is Possible to Get Stuck In Cased Hole
Problem Prevention
Inadequate Hole Cleaning Moderate Angle Wells (30° <Incl < 60°)
Take Preventive Actions Agitate Cuttings Beds
• Rotate DP at 150+ RPM if possible
• Reciprocate & Rotate While Circulating Bottoms Up Maximize Annular Velocity
• Larger Drill Pipe
• Larger Jets Make Wiper Trips Back Ream Out Of Hole - Carefully!
Problem Prevention
Inadequate Hole Cleaning High Angle Wells (Incl > 60°)
Cuttings Beds Form, But Are Stable Hole Cleaning Usually Not A Problem in High
Angle Section Cuttings Beds Potential Problem on Trips Back Ream Out of High Angle Section Reminder - All High Angle Wells Have a
Moderate Angle (Problematic) Section
Problem Prevention
Inadequate Hole Cleaning
Causes Inadequate Mud Flow Properties Too Low an Annular Velocity Cuttings Beds in Directional Holes
• Angle < 30º - Minimal Problems
• Angle > 60º - Minimal Problems
• 30º < Angle < 60º Problem Area
Inadequate Hole Cleaning
Prevention Keep Mud in Good Shape Watch Shale Shaker for Too Few Cuttings Pump More Fluid (Increase AV) Run High / Low Viscosity Sweeps Use Larger Drill Pipe Avoid long 30º to 60º Angle Sections Make Wiper Trips (Ream Out w/ Top Drive)